参数为空，返回错误提示

app/enterprise/controller/Group.php

@@ -353,6 +353,9 @@ class Group extends BaseController
       public function setNotice(){
          $param = $this->request->param();
          $uid=$this->userInfo['user_id'];
+         if (!isset($param['notice'])) {
+             return warning(lang('system.notNull'));
+         }
          // 公告内容检测服务
          event('GreenText',['content'=>$param['notice'],'service'=>"comment_detection"]);
          $group_id = explode('-', $param['id'])[1];